1. Technical Field
This disclosure relates generally to a turbine engine and, more particularly, to a combustor for a turbine engine.
2. Background Information
A floating wall combustor for a turbine engine typically includes a bulkhead that extends radially between inner and outer combustor walls. Each of the combustor walls includes a shell and a heat shield which together define cooling cavities radially therebetween. These cooling cavities fluidly couple impingement apertures in the shell with effusion apertures in the heat shield.
During turbine engine operation, the impingement apertures direct cooling air from a plenum adjacent the combustor into the cooling cavities to impingement cool the heat shield. The effusion apertures direct the cooling air from the cooling cavities into a combustion chamber to film cool the heat shield. This cooling air subsequently mixes with a fuel-air mixture within the combustion chamber, thereby leaning out the fuel-air mixture in both an upstream fuel-rich primary zone and a downstream fuel-lean secondary zone. The primary zone of the combustion chamber is located between the bulkhead and the secondary zone, which is generally axially aligned with quench apertures in the combustor walls.
In an effort to increase turbine engine efficiency and power, temperature within the combustion chamber may be increased. However, increasing the temperature in the primary zone with a relatively lean fuel-air mixture may also increase NOx, CO and unburned hydrocarbon (UHC) emissions.
There is a need in the art for an improved turbine engine combustor.